GeminiFocus 2017 Year in Review | Page 57

for the newest member of the DSSI family because it is very agile and quick . The new dual-channel instrument will have a larger format than the previous version , modern Electron Multiplying CCD cameras , and both speckle and wide-field imaging capabilities with standard Sloan Digital Sky Survey filters . One of the unique features of DSSI is its robust and compact design , and ‘ Alopeke will take full advantage of this .
‘ Alopeke will be permanently mounted on Gemini North in a location that does not interfere with the standard instrument ports — so users can operate it in visitor mode ( when time is allocated through the Time Allocation Committee ) without the additional overhead of mounting and then removing the instrument . This innovative placement will permit us to offer ‘ Alopeke at each Call for Proposals . It will be remotely operable from the Hilo Base Facility . The instrument team will make the observations and provide their standard pipeline-reduced data products to Principal Investigators . We will make the data available ( after the standard proprietary period ) via the Gemini Science Archive ( in a reduced-effort mode ).
In addition to other types of science , speckle observations are viewed as a critical part of the exoplanet validation process , providing essentially the only method to validate small , rocky planets . ‘ Alopeke will be ideal for characterizing a system of low mass planets , such as that orbiting the late M-type star , TRAPPIST-1 ( Figure 14 ). Previous observations of that star , which is only about 8 % the mass of our Sun , showed variations in the flux which suggested the presence of several Earth-sized planets . The situation could be much more complicated than that , however , if TRAPPIST-1 were part of a binary or multiple star system . The resolution afforded by DSSI on Gemini South allowed astronomers to see closer to TRAP- PIST-1 than the orbit of Mercury to the Sun , and effectively ruled out the existence of any stellar or sub-stellar companion .
We expect ‘ Alopeke to have even better performance than DSSI . It will be mounted on the Gemini North telescope permanently and will be available for continued observations of this sort in the future .
— Alison Peck and Steve B . Howell
Figure 13 . This image shows some steps in the process of Speckle Image reconstruction using Fourier transform techniques . Left : A single 50 millisecond speckle image of a star . Middle : a conventional image typical of a groundbased telescope . Right : A reconstructed image revealing the star is really a close binary pair . The boxes are ~ 1 arcsecond on a side . Credit : Elliott Horch
For more information on the Gemini Visiting Instrument Program , what capabilities to expect in coming semesters , or how you can bring your instrument to Gemini , email : gemini-vip @ gemini . edu
Figure 14 . Artist ’ s impression of the TRAPPIST-1 exoplanetary system showing three Earthsized planets in orbit around the low-mass star . Observations characterizing this system were made using DSSI on Gemini South last year . Credit : Robert Hurt / JPL / Caltech
January 2018 / 2017 Year in Review GeminiFocus
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